The word "瓢泼" is formed by combining the character "瓢", meaning a gourd ladle or dipper used for scooping liquids, with "泼", meaning to splash or pour. Together, they create a vivid compound where "瓢" acts as a metaphorical tool and "泼" as the action, depicting rain so heavy it appears as if being poured from a dipper, thus conveying the sense of torrential downpour.